# Define here the models for your spider middleware
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/spider-middleware.html
import random

from scrapy import signals
from scrapy.core.downloader.handlers.http11 import TunnelError

from util.ip666 import get_long_ip

# useful for handling different item types with a single interface
from itemadapter import ItemAdapter


class MyScrapySpiderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the spider middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_spider_input(self, response, spider):
        # Called for each response that goes through the spider
        # middleware and into the spider.
        print("爬虫启动")
        # Should return None or raise an exception.
        return None

    def process_spider_output(self, response, result, spider):
        # Called with the results returned from the Spider, after
        # it has processed the response.
        print("爬虫结束")
        # Must return an iterable of Request, or item objects.
        for i in result:
            yield i

    def process_spider_exception(self, response, exception, spider):
        # Called when a spider or process_spider_input() method
        # (from other spider middleware) raises an exception.

        # Should return either None or an iterable of Request or item objects.
        pass

    async def process_start(self, start):
        # Called with an async iterator over the spider start() method or the
        # maching method of an earlier spider middleware.
        async for item_or_request in start:
            yield item_or_request

    def spider_opened(self, spider):
        spider.logger.info("Spider opened: %s" % spider.name)


class MyScrapyDownloaderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the downloader middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_request(self, request, spider):
        # Called for each request that goes through the downloader
        # middleware.
        print("请求")
        # request.headers = {"user-agent": "4444"}
        # Must either:
        # - return None: continue processing this request
        # - or return a Response object
        # - or return a Request object
        # - or raise IgnoreRequest: process_exception() methods of
        #   installed downloader middleware will be called
        return None

    def process_response(self, request, response, spider):
        # Called with the response returned from the downloader.
        print("响应hiuiohoiuho")
        # Must either;
        # - return a Response object
        # - return a Request object
        # - or raise IgnoreRequest
        return response

    def process_exception(self, request, exception, spider):
        # Called when a download handler or a process_request()
        # (from other downloader middleware) raises an exception.

        # Must either:
        # - return None: continue processing this exception
        # - return a Response object: stops process_exception() chain
        # - return a Request object: stops process_exception() chain
        pass

    def spider_opened(self, spider):
        spider.logger.info("Spider opened: %s" % spider.name)


class ProxyPoolMiddleware:
    @classmethod
    def from_crawler(cls, crawler):
        s = cls()
        # s.proxy_poll = get_proxy_poll(1)

        s.proxy_poll = []
        return s

    def process_request(self, request, spider):
        if len(self.proxy_poll) == 0:
            self.proxy_poll.append(get_long_ip(1))
        ip = random.choice(self.proxy_poll)
        print(f'使用代理{ip["http"]}发起请求')
        request.meta["proxy"] = ip["http"]
        request.meta["ip"] = ip

    def process_response(self, request, response, spider):
        return response

    def process_exception(self, request, exception, spider):
        if isinstance(exception, TunnelError):
            ip = request.meta["ip"]
            print("代理异常", ip["http"])
            if ip in self.proxy_poll:
                self.proxy_poll.remove(ip)
                self.proxy_poll.append(get_long_ip(1))
            ip = random.choice(self.proxy_poll)
            request.meta["proxy"] = ip["http"]
            request.meta["ip"] = ip
            print("发起请求")
            return request
